Long term, this concerns me about Nikon's future. That, and they do not engineer their own sensors anymore.

Nikon engineers their own sensors, jointly with Sony and now with Toshiba. Do you really think that Toshiba did the new (awesome) D5200 sensor all by themselves?

Nikon is also in no way making every other part inside their cameras. This is the same as any electronics company or car manufacture, the primary company engineers the car and parts, others manufacture the parts and they are assembled in a Nikon plant.